THE VICTORIAN NATURALIST. 



tralia and New Zealand, whereby undoubtedly seeds of plants, 

 which were carried by heavy storms from South America in a 

 southerly direction to the antarctic glaciers, could subsequently 

 have been transported with the antarctic drift ice eastward, and 

 which on their arrival in Australia found the same climatic con- 

 ditions as in the country from which they had departed. The 

 occurrence of certain species, which we find common to most 

 of the southern islands of the Pacific, New Zealand, and 

 the southern part of Australia (Hooker), strongly indicates that 

 the trend of this drift must have passed through these parts. 

 How is such a close relationship of some of our genera, such as 

 Gaultiera, Colobanthus, Caltha, Claytonia, Oreomyrrhis, Azorella, 

 &c., with South American alpine forms to be otherwise ex- 

 plained ? 



With the retreat of the glacial period came hand in hand an 

 increase of warmth, which gave the flora in the north and north- 

 west of the Alps the opportunity to again recover their lost 

 territory, from which they had with the advance of the glacial 

 period to retire step by step. The struggle could now begin, and 

 thus were these new arrivals from the east, which had mixed with 

 our flora in the extreme south, where, during the culmination 

 point of the glacial period, there was yet sufficient room left for 

 their livelihood, driven to higher altitudes, for only in such 

 situations could they find the cool climate to which they were 

 accustomed, only there could they remain as masters of the 

 battle-field, where they at present make their show as witnesses 

 of that grand phenomenon, the glacial period. 



The fact that the Antarctic had — as it is often assumed — in 

 Miocene time a climate which could have given higher developed 

 plant forms the necessary conditions for their existence cannot 

 be entirely overlooked in our question, and it is quite certain 

 that under such conditions an exchange of species of the South 

 American and Australian flora over the Antarctic could have 

 taken place. As the geographical situation of South America is 

 more favourable for such a distribution than that of Australia, the 

 relation of Antarctic species to South American and vice versd 

 should have been greater than to those of Australia. For that 

 reason it does not seem probable that our Australian flora would 

 have been influenced directly by the Antarctic flora at the above- 

 mentioned period, but that the glacial period (in Tertiary times) 

 was the main factor to establish a relationship between the Aus- 

 tralian alpine and the South American flora. 



As long as our knowledge in phyto-palaeontology remains 

 stationary, the discoveries of which are of invaluable importance 

 in the question of the history of our plant life, so long will we 

 walk in the dark and have to depend on hypotheses which throw 

 only an uncertain light on the wonderful work of nature during 



